import {useIntersectionObserver} from "@vueuse/core";

export const lazyPlugin = {
  install(app) {
    //懒加载指令逻辑
    app.directive("img-lazy", {
      mounted(el, binding) {
        // el: 指令绑定的那个元素 img
        // binding: binding.value  指令等于号后面绑定的表达式的值  图片url

        const {stop} = useIntersectionObserver(el, ([{isIntersecting}]) => {
          if (isIntersecting) {
            // 进入视口区域
            el.src = binding.value
            stop()
          }
        })
      }
    })
  }
}
